Electric switch



F. GROPP ET AL ELECTRIC SWITCH Filed Jan. 6' 1927 mm, w a DH ,M

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Patented Jan. l0, 1928.

UNITED STATES PATENT OFFICE.

FRIEDRICH GROPP, OF BERLIN, AND MAX BUTTERLIN, F NEUBABELSBERG, GER-MANY, ASSIGNORS TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

ELECTRIC SWITCH.

Application led January 6, 1927, Serial No. 159,421, and in GermanyFebruary 25, 1926.

Our invention relates to electric switches and particularly to electricswitches of the iiuid break type. An object of our invention is theprovision of an improved switch of the fluid break type, the casing ortank of which is shaped to be better able to withstand internal pressureand is constructed to resiliently yield to such pressure. Another objectof our invention is the provision of means responsive to a yieldingmovement of a portion ofthe casing or tank for directing a stream of arcextinguishing liquid between the contacts.

Our invention will he better understood from the following descriptiontaken in connection with the accompanying drawing, and its scope will bepointed out in the appended claims.

Referring to the drawing, Fig. 1 is a sectional view of a fluid breakswitch embodying our invention and Fig. 2 shows a modifcation thereof.

By way of illustration we have shown our switch supported on a base 1 bymeans of a framework 2 comprising a channel 3 and plate 4. The switchcontacts are inclosed by a casing comprising two globular orsemispherical cooperating portions 5 and 9. The portion 5 constitutesthe cover member through which extend the insulator bushings 6supporting the fixed contacts 7, and it 1s mounted in a fixed positionon the plate 4. The lower member 9 is arranged to slide within the uppermember and hold the insulating liquid 10 in which separation of thecont-acts takes place. Member 9 has guide pins 1l which slide in theslide rails 12 forming part of the supporting frame-work. The movablecontacts 13 are connected by the bridging member 14 and are arranged tobe actuated by mechanism not shown connected to the operating rod 15.Below the switch casing and resting on the base 1 is the cylinder 17 inwhich slides the piston 18 secured by the rod 19 and supporting disk 20to the lower member 9. Coil spring 21 between disk 20 and the cylinderserves to carry the weight of the lower member and associated parts andto return them to their uppermost position after being depressed 'bypressure within the casing. The space in the cylinder 17 below thepiston is filled with the same insulating liquid as that in which thecontacts 7 and 13 are immersed.

Pipes 22 connect this space with the Contact casing being extended intoits casing to a point near the contacts. In the tubes 22 are filters 23for removing foreign matter from the oil before it reaches the contacts.Near the edge of the lower member of the casing are shown openings 24which when the member is suficiently depressed communicate with a.recess 25 in the wall of the upper member to permit the escape of gas.

Whenever in opening the switch the pressure in the casing reaches apredetermined value the lower casing member is depressed against thespring 21 and insulating liquid is forced through the pipes 22 in astream toward the contacts thereby assisting in extinguishing the arcbetween the contacts. After the circuit has been interrupted the springwill return the movable parts to their original positions and in thismovement insulating liquid in the casing -will be drawn back through thepipes into the cylinder.

In the modified form of our invention shown in Fig. 2 which has amounting similar to that shown in Fig. 1 the lower member 30 of thecasing is provided with passages 31 in the walls thereof which openingscommunicate through the hollow rod 32 with the space below the piston18. Passages 31 terminate in inwardly directed openings 33 whereby whenthe lower member of the casing is depressed by pressure in the casing astream of insulating liquid is directed toward the contacts and into anarc therebetween.

What we claim as new and desire to secure by Letters vPatent of theUnited States, is:

1. A. fluid break switch having cooperating contacts, a casing thereforcomprising portions relatively movable in response to internal pressure,and means actuated b the movement of one of said portions for d1-recting a stream of insulating liquid against said contacts.

2. A fluid break switch having cooperating contacts, a casing thereforcomprising a iixed upper portion and a relatively movable lower portion,means for resiliently opposing downward movement of said lower portion7and means responsive to downward movement of said lower portion fordirecting a stream of insulating liquid into an are drawn between itscontacts.

3. A iuid break switch having coo erating contacts, a casing containingins atin liquid in which the contacts are immerse said casing comprisinga fixed upper memi 5 ber and a resiliently mounted lower member, areceptacle containing insulating liquid, a plunger therein connectedwith said lower member and means for conducting liquid from saidreceptacle to the vicinity of said contacts. v

In witness whereof, We have hereunto set our hands this 21st day ofDecember, 1926. FRIEDRICH GROPP. MAX BUTTERLIN.

